A fast general-purpose hardware synchronization mechanism
John T. Robinson · 1985
One way to reduce the overhead of concurrency control m a multiprocessor transaction processmg system 1s to implement an underlying synchromzatlon mechanism or a simple global concurrency control dlrectly m hardware The problem with this approach 1s that a strong comnutment may then be made to a partlcular synchromzatlon protocol, and so the resultmg hardware mechamsm may be useful m only a very narrow range of systems A solution 1s possible usmg a table-dnven approach However, a straightforward table-dnven approach 1s lmpractlcal due to the extremely large table sEes required for many protocols It 1s shown here that this problem can be solved by reducmg the table sizes reqmred by makmg use of the processor symmetry that occurs m most systems The resultmg algorithm for a table-dnven synchromzatlon mechamsm 1s not only general-purpose but also extremely fast An example hardware unplementatlon of tis algonthm 1s presented, and practical expenence usmg this approach 1s described